Modern libraries have experienced increased demands from patrons, in terms of needs for larger and larger holdings of books and other tangible materials. Accordingly, it is not uncommon for public libraries, for example, to handle collection and distribution of hundreds of thousands, or even millions, of books and materials. Tasks of librarians in handling these ever increasing volumes are often overwhelming.
Particularly problematic librarian tasks involve receiving, sorting, and ultimately re-shelving material returned from patrons. Tasks of manipulating materials in receiving, sorting, and re-shelving, are tedious and have lead to repetitive stress-type physical injuries. These injuries result, for example, from repetitive bending of the librarian's body while reaching into a books and materials receiving area, then grasping each book or piece of material and lifting and/or moving it from the receiving area to a sorting area, and then finally again lifting and/or moving the material to a re-shelving area.
In attempts to minimize these problems, procedures have been developed to provide some degree of automation in such receiving, sorting, and re-shelving tasks. For example, librarians commonly employ wheeled carts to transport material to be re-shelved. However, use of such carts does not adequately address the "front end" problem associated with the aforementioned repetitive bending and lifting.
In general, aside from library applications, attempts have been made to respond to problems associated with repetitive bending, grasping, and lifting and/or moving materials.
For example, U.S. Pat. No. 4,357,127 entitled "Apparatus For The Stacking Of Objects" issued to Kooiman provides an apparatus for stacking objects, such as trays, plates, and the like, in which an uppermost one of the objects in a stack is maintained at a height independent of a number of objects in the stack. Kooiman teaches the use of a stack carrier contained within a vertically arranged open top container, with the stack carrier being suspended within the container by means of tension springs. The tension springs react in proportion to a load imposed upon them by a stack, thereby maintaining uppermost objects in the stack at a desired height.
In U.S. Pat. No. 4,545,463 entitled "Vertically Adjustable Picking Box" issued to Olovsson, a liftable and lowerable picking box for storing workpieces at a workplace is provided. Therein, a hydraulic foot-actuated pump provides a vertical lifting and lowering action on the box.
U.S. Pat. No. 4,629,072 entitled "Apparatus For Storing And Dispensing Stacked Articles" issued to Loew teaches the use of a torsion spring to provide presentation of an uppermost object in a stack at a predetermined height.
U.S. Pat. No. 4,919,275 issued to Futch, and U.S. Pat. Nos. 4,954,760 and 5,013,983 issued to Futch et al., each being entitled "Self Leveling Dispenser" disclose a rack supporting a stack of trays within a frame. A reversible motor connected to spiral shafts mounted at comers of the frame rotates the shafts in jackscrew-like fashion, to provide vertical movement of the rack. Further employed are sensors, which cause the reversible motor to be driven, with resultant shaft rotation and vertical movement of the rack. The sensors enable positioning of an uppermost tray in the rack to a desired vertical height position.
Yet another, U.S. Pat. No. 5,626,206 entitled "Device For And Method Of Vertically Adjusting Parts In A Bin" issued to Weber et al. teaches use of a scissors-type jack or suitable lifting means for lifting a platform that supports parts in a parts bin.
The aforedescribed patents however, and particularly the spring-loaded devices thereof, rely upon initial spring calibration and mechanical integrity of the spring systems. Furthermore, the motor or hydraulically driven devices are noisy and are not well suited to handling library materials in a library environment.
Commonly, a library employs use of an outside "drop box" for receiving returned library materials both for convenience and after hours receiving of the returned library materials. A "drop box" is sometimes used inside the library. Usually, ordinary deep well receiving carts or boxes are positioned below a chute associated with the "drop box" for receiving the library materials. Since the library materials are generally non-uniform and of differing kinds of materials (i.e., books, audio tapes, video tapes, and the like), the library materials will stack in these receiving carts in a totally random order.
A problem with aforementioned receiving carts is that when empty, the first received object or library material will fall from the vertical entrance point (the top of the cart) until stopped by the fixed position of the floor of the receiving cart, possibly causing damage to the received library material. As library materials continue to be received, the materials will randomly stack. The quantity of materials that are received by the cart is, of course, dependent upon the height of the walls of the cart. However, the higher the walls, the more difficult is the process of emptying in the cart, i.e., bending and reaching for the materials at the bottom of the receiving cart.
Thus, there exists a need for library receiving bin or container which has a floor which is maintained at substantially a constant height or pre-set access level for both loading objects into, or removing objects from the floor of the bin, which is easy to operate, and that provides quiet operation, and which accommodates the non-uniform and differing types of library materials.